The aim of the invention is to achieve the smooth circulating movement of a roller, and further prevent the fluctuation of a roller chain at the time of the circulating movement. Roller chain guide parts by which a trajectory of a roller chain is guided on the predetermined trajectory, are arranged in a roller return passage and a direction switching passage inner circumferential guide part, and at least any one of a roller return passage forming member forming the roller return passage and a direction switching passage inner circumferential part forming member forming a direction switching passage inner circumferential part, is integrally formed by inserting a block main body in a metal mold. |